Retailers of goods and services typically offer such goods and services for purchase via one or more conventional brick-and-mortar retail stores. It may be desirable for retailers to offer a shopper membership service program to their customers for the purpose of offering shopping benefits and/or tracking customer purchases over time. It may further be desirable to include in such a shopper membership service program a mechanism via which customers can pay for purchases using an instrument of electronic funds transfer in a manner that does not require the customers to produce or supply a tangible form of the instrument at the point-of-sale.